Generally, laminated sheets and cards that contain holographic, metallic, and/or reflective features are constructed from multiple layers of chemically different materials, such as plastic or paper based substrates, films or foils that are holographic, metallized, reflective, printed, or clear, adhesives, and other coatings. Laminated sheets and cards may also include printing, graphics, additional holographic elements, security inks, and other features. Typical uses of laminated sheets include use in packaging, signage, displays, and the like. Laminated sheets can also be used to produce laminated and non-thermally laminated cards, such as credit cards, identification cards, phone cards, key cards, gift cards, etc.
Commonly, full face metallic and holographic cards are made with a metallic or holographic polyethylene terephthalate (“PET”) film laminated into or onto a polyvinyl chloride (“PVC”), acrylonitrile butadiene styrene terpolymer (“ABS”), or polycarbonate (“PC”) card body or substrate. However, the different material characteristics of the film, card body, and/or substrate prevent the cards and skeletons from which the cards are die cut from being readily recyclable, biodegradable, degradable, or compostable.
Other issues arise in the production of these laminated cards, which must ultimately meet certain standards with respect to peel strength or resistance to delamination, for example, for practical use. Defects such as bubbles or wrinkles between layers, orange peel, warping, curling, or bowing of the final laminated cards may occur during or after the manufacturing process. Warping, for example, may occur as a result of a roll laminating process, wherein rolls of material that make the layers are adhered together as they are unrolled, coated, and fed into a lamination press with unbalanced tension. Further, such roll-to-roll laminating typically includes heavier plastic materials that are wound up and thus take on roll set curl.
Within a composite or mixed material card, a balanced, symmetrical construction is commonly required in order to prevent curling or bowing in laminated cards. For example, in a symmetrical construction, even if only one side of the card requires a laminated PET film, such as a metallized film or reflective surface, the opposite side of the composite construction will include a matching PET film type. Accordingly, one such known card laminate comprises a split core substrate of two adjacent layers of 12 mil (300 micron) white PVC copolymer core stock. Laminated to one side of each of the PVC split cores is 0.75 gauge (19 micron) or 0.92 gauge (23 micron) PET holographic, metallized, brushed, coated, printed, or clear film, with or without a tie coat. A tie coat or primer may be used to improve the bond between the adhesive and the metallized surface of the film. This lamination involves a roll-to-roll lamination process.
The above-described card laminate has various drawbacks, for example, PVC in roll form due to roll set curl can cause sheet curl and rippled edges, printed sheets can curl or exhibit other dimensional instabilities when heated in a drying oven or under UV lights, and PVC in roll form may limit certain product constructions. The roll-to-roll laminating process may further require specialty sheeting to achieve registered imagery, heavier adhesive coat weights that can create visual defects, and a final lamination cycle to activate adhesive and achieve peel strength requirements for typical end uses, such as ANSI/ISO specifications.
The laminate sheets and cards of the present disclosure, however, overcome one or more of the problems and disadvantages of prior art laminate sheets and cards.